Hydronic molecules and the charmonium atom
Voloshin M.B., Okun' L.B.
We consider the possible existence of levels in a system consisting of a charmed particle and a charmed antiparticle; these levels result from exchange of ordinary mesons (ω,ρ,ε,φ, etc.). An interpretation of the resonances in e +e _ annihilation in the region 3.9^4.8 GeV is proposed.